there EAISLY can be a Definiteive batman, so long as the version hits all the points of the character that have the "ESSENCE" of what makes batman, batman.
but what makes up that "essence"? that's the key.Distilling the character down to some core, essential truths, and then writing him in a story that shows EACH of these aspects.
1) the world's Greatest Detective - This is CENTRAL to batman. He is at his VERY core something of a modern day Sherlock Holmes. Missing this, would be akin to Making Superman without ANY of his powers, and no intention of having him ever get those powers. Batman's detective skills are generaly equal parts Technology driven, and personal honed ability. I think it's best to continue in that vein, however, that's personal preference.
2) Batman ALLWAYS wins in the end, Becuase he ALLWAYS has a plan. He makes plans, then he makes backup plans for those plans, and extra continginces for those as well. He may get taken down in the first round, but he will then adapt, and come back swinging.
3) Batman is someone possessed of genius-level intellect. He's smart. HE's OBSCENELY smart. this needs to be demonstrated in some way.
4) the toys - Batman is in part defined by his very advanced technology. some of it he's designed himself, due to his intelegence. Some of it comes from Wayne Ent, either via RnD, or developed by a company he bought.
5) The Wealth - He's Rich. nuff said.
6) Martial arts - Bruce Wayne has trained extensively in several different forms to gain his skills. he's not just some loww- level brawer. He's a master. Combat he is involved in should showcase this. He is a master. his moves should be planned, strategic, thought-out, and graceful. If this means pulling in a master martial artist as a stunt double, then it needs to be done. This ALSO means his suit needs to be something he can ACTUALY move in.
7) Fear as a weapon. BATMAN chose to become a bat to strike terror into the hearts of criminals. he NEEDS to be some flavor of spooky.
8) Levity - All that grimness and terror can take their toll. he needs SOME degree of humor, and levity. Even if it is small, and mostly insignifigant, it NEEDS to be there somewhere.
9) Robin - I'm sorry, Batman NEEDS Robin. Robin has been with Batman since ALLMOST the begenning. He joined Batman one Year AFTER the comics were published. batman had a whopping 10 books before he was given his young apprentice. He's as essential to Batman as any of his villians. You can go with the more mature Nightwing, and have him around some, but mostly off doing his own thing, but he Needs to be there in some form.
10) Bruce Wayne, Millionaire Playboy - The nolan films did an excellent job of this is Batman Begins. Bruce wayne needs to be shown as a public figure, who seems fairly narcicisitic, and as far the opposite of what batman is. Bruce is only REALLY himself with those he consideres his family, the Person he is in public is just another mask.
11) A man among gods - Batman, is just a normal guy in a suit, with training, money, and expensive gadgets. He is still something that any normal person COULD become, given enough time and money. Yet he hangs around with Heroes like superman, wonder woman, flash, ETC, that are borderline gods. Many of the times, he comes out better than they do. so for all of his frailties, and faults, he's a story about the triumph of the human spirit. This necessitates placing batman in a larger world with other superhero's. Again, like Robin, they don't need an overwhelming presence all the time, just a nod, or accnoledgement that they exist at all.
12) My Parrents are DEEEEEEEEEEEAD! - Batman does what he does, so that no one else, hopefully, will ever have to suffer like he has. His motives are strangely altruistic. Additionaly, he has become a monster, to fight monsters, so that no one else must.
There you go. 12 items. include them, you have a definiteive batman.